In 1932, the Times merged with the rival St. Louis Star, and Muchnick left the paper for a position as Packs' publicist, where he handled public relations, finances and even booking duties.

However, Muchnick was insulted when Packs awarded him a paltry $200 bonus following the duo's successful promotion of the Joe Louis vs. Tony Musto heavyweight title bout in April 1941 (a fight that drew profits of $14,000).

Despite facing heavy resistance from Packs (who possessed much political clout with the State Athletic Commission), Muchnick promoted his first shows in May 1942 before enlisting in the Air Force during World War II.

Upon returning, Muchnick continued to face competitive pressures from Packs; though he filed several court injunctions to promote his first show at St. Louis' renowned Kiel Auditorium on December 5, 1945.

With the help of maverick Ohio promoter Jack Pfefer (who sent Sam several wrestlers to help him get started), Muchnick drew 3,771 fans to the arena while featuring such veteran wrestling stars as Ed "Strangler" Lewis, Roy Dunn, and others.

As a result, on July 19, 1948, Muchnick met with fellow promoters Pinky George, Wally Karbo (representing Tony Stecher), Orville Brown, Max Clayton, and Al Haft at the President Hotel in Waterloo, Iowa to form what was named the National Wrestling Alliance.

As a result, he was then able to secure the services of an innovative young heel named "Nature Boy" Buddy Rogers, who had previously been wrestling in Jack Pfefer's Toledo, Ohio territory.

Rogers' outspoken persona and charismatic personality allowed him to outdraw even the great Lou Thesz (who by now had taken over much of Tom Packs' operation) while adding legitimacy to Muchnick's company.

Eventually, the two St. Louis groups would merge while starting a promotional war angle; Muchnick kept a controlling interest in the territory by holding two percentage points more than Thesz.